A strong 6.1-magnitude earthquake struck off the coast of Crete early Thursday, alarming residents and tourists. The quake occurred at 6:19 a.m., about 49 miles from Heraklion at a depth of 68 km, according to the USGS.

The European-Mediterranean Seismological Centre (EMSC) issued a tsunami warning, urging residents of Greece, Turkey, Italy, France, and Portugal to stay alert and check for updates.

Tremors were felt across the Aegean Sea, parts of Turkey, and even Israel. “Everything shook like mad, never felt one that strong,” reported a local in Malia. In Schisma Elounta, another resident said, “The whole room was shaking.” The tremor lasted up to 30 seconds, waking many in the middle of the night.

Tourists shared their fear online. One British visitor posted: “That’s been two earthquakes in the past week. I just want to get home safely.” Another said she was staring at the sea, wondering if it looked “any different.”